Ductless split system makes for a good retrofit add-on to houses with “non-ducted” heating systems, such as boilers with radiant and in floor heat, as well as space heaters. They can also be a good choice for room additions where extending or installing distribution ductwork is not an option, and very efficient new homes that require only a small space conditioning system.
The main advantages of going ductless are that there small, quiet, and have the flexibility of installation almost anywhere. This can give you control with zoning of certain areas that you want heated or cooled. Mini splits have no ducts so they avoid energy loss associated with ductwork. Ductwork can account for 30% of energy consumption for space conditioning.